Sound reproducer



Oct. 24, 1933. E. J. QUINBY ET AL 1,931,681

SOUND REPRODUCER FilBdFBb. 19, 1931 INVENTORS EDWIN JAY QUINBY BY 6(EORGP. H INS ATTORNEY Patented Oct. 24, 1933" UNITED STATES PATENT OFFICESOUND REPRODUCER Edwin Jay Quinby, Yonkers, N. Y., and George P.Hopkins, Camden, N. J assignors to Radio Corporation of America, acorporation of Delaware Application February 19, 1931. Serial No.516,904

' 6 Claims.

at the same time, is arranged to provide desired acoustic properties.

In many instances it hasbeen necessary'to locate sound reproducers outdoors in places where they have been exposed to the elements with, insome instances very detrimental results.

The general mounting of sound reproducers out "doors is in itselfobjectionable, unless some means is provided for protecting thereproducers from the elements and from damage through tampering with thereproducers by unauthorized persons. 1

It is the object of the present invention to overcome the objectionablefeatures set forth hereinbefore and to provide means for protecting theacoustic reproducers from the elements and for preventing undesiredtampering with the reproducers.

Another object of the invention is to arrange the protecting means in amanner such that it will have desired acoustic properties among whichmight be mentioned 1) baffle properties, '(2) directional horn effect,and (3) ventilation for the enclosure at the back of the cone. 1

Other and more specificobjects of the invention will become apparentupon reading the following specification and appended claims inconnection with the accompanying drawing in which,

Figure 1 is a side view of the device showing the reproducer in dottedlines.

Figure 2 is a front view of the device and Figure 3 is a view takenalong line 33 of Figure 2.

Referring to the figures inwhich like parts are indicated by likereference numerals, the sound reproducer is indicated generally at 1.The reproducer may be of any type such as for example, the moving coilor electrodynamic type. It consists primarily of a framework orbody-portion 19 carrying a driving apparatus and a diaphragm usuallyconical in form. The dimensions of the diaphragm may be varied to meetthe existing problem throughout a rather wide range. It has been foundhowever, that a diaphragm approximately 8" in diameter will give verygood results.

When the sound reproducer is of the dynamic type it may also include afield rectifier unit,

but may be closely associated therewith and protected by the samehousing.

Around the loudspeaker 1 is arranged a housing 2 which in thisparticular modification is given substantially the shape of aknightshelmet. The housing or casing 2 hasa narrow neck portion 3, anenclosing or head portion 4 and a shoulder portion 5. It is alsoprovided with a visor 6 covering an opening in the enclosure or' headportion 4 and through which the mechanism may be serviced. The visor isprovided with one row of ventilating louvres '7 and one'row of falselouvres 8. The visor may be attached to the helmet in any suitablemanner but it has been found very desirable to have it pivoted at points9 and 10.by means of cap screws. As a result of this arrangement thevisor-can easily be removed entirely. In some instances it has even beenfound desirable to apply 'a' caulking material around the upper edge 13of the visor. mounting clamps 11 and 12 areprovided at the back of thecasing or helmet 2.

The sound reproducer is mounted so that the diaphragm is substantiallyat the neck portion of the helmet. The loudspeaker may be arranged sothat the diaphragm'is either directed vertically downwardly or at anangle to thecentre line of'the helmet, as shown in the figures. Thedriving mechanism andany associated apparatus extend into the headportion 4.

The head portion-4 is designed so as to form an enclosure portion havingdesired acoustic properties behind the diaphragm. The enclosurecommunicates with the open air by means of the ventilating louvres 7.This communication prevents the setting up of an air pocket in back ofthe diaphragm which would tend to add stiffness to the diaphragmand inother ways to damp the diaphragm motion. The louvres 7 are covered witha suitable screen as indicated at 20 to .95 protect the mechanism fromthe weather. It should be noted, however, that they are under thelargest part of the head portion 4 and are thus protected from theelements to a considerable extent.

The shoulder portion 5 is arranged so as to serve as a short horn whichincreases considerably incross sectional area or flares outwardlytowards its lower edge 21. Its purpose is to direct the sound into thedesired area and at the same time to give an acoustic amplification. Themouth of the horn or shoulder 5 is open to the atmosphere, but thediaphragm of the sound reproducer is itself preferably provided with theusual form of grille as indicated at 22. The

mounting clamps 11 and 12 may be of any suitable design and arrangementdepending upon the structure by which the helmet is to be supported.

The helmet may be or any suitable material such as metal or alloythereof and it may be shaped iii-any well .known manner. it has beenfound eastaluinihum helmets give very good results as they are noteasily tarnished by the weather and because this metal is or anonresonant character. It would of course also be possible to usehelmets made of any composition which could be molded or otherwiseshaped. But it is highly desirable that the metal or composition besubstantially non-resonant or at least that it does nothave a resonantfrequency within the audible range.

The helmet when made from a metal such as aluminum may be polished or ifdesired may be painted any desirable color. The helmet is provided withplumes 14 which are preferably made or sheet oopperand painted suitablecolera. It has been ioundthat a highly polished aluminum helmet withplumes painted in bright colors gives a very desirable and attractiveeduct. and that this arrangement at the same time provides the desiredacoustic and protective prop-- crtiea. l

While a preferred arrangement has been demribed it is m be understoodthat the shape and design can be varied to some extent so long as thegeneral acoustic and protective means are met. It is to be understoodtherefore, that the invention is not to be restricted to the particularacoustic arrangement or design shown but that any similar arrangement ormodification thereof which will fall within the scope of the appendedclaims is considered as a part or the invention. What we claim is:

a 1". Apparatus for reproducing sound comprisin; a sound reproducerhaving a diaphragm and a body portion, and a casing for said reproducer,said casing having a portion adapted to receive and enclose the body orsaid reproducer. a narrow portion adiacent the diaphragm, a. horn likeportionror the sound waves, from the diaphragm and a closure member forsaid narrow portion to n-event sound waves emitted in the nrstnamedcasing portion from passing into said horn portion.

2. A housing for a sound reproducer comprising a single verticallyarranged body closed at its top surface and one side and having anenclosure portion for the sound reproducer, and a downwardly directedhorn portion for the sound waves set up by the sound reproducer, theeffective length of said horn portion being substantially less than thatof said enclosure portion.

' 3. A housing for a sound reproducer comprising a single body having anenclosure portion for the sound reproducer, openings in said enclosureportion, and a horn portion for the sound waves fromsaid'soundreproducer and means acoustically separating said enclosure portion fromsaid horn portion.

1 4. An acoustic device having the shape of a knights helmet consistingof a. casing, having a neck portion, a head portion and a shoulderportion, an acoustic reproducer mounted with its diaphragm substantiallyat the neck portion and its operating mechanism in the head portion, avisor mounted on said head portion, louvres in said visor for providinga communication between the interior of said head portion and the openair,

and means on said helmet for supporting the helmet from a supportingstructure.

5. In combination, a casing having curved sides which are taperedinwardly to meet at its top and which are flared outwardly to form ahorn portion near its base, a loudspeaker mounted across said casing andserving to subdivide it into upper and lower compartments one or whichis said horn portion, the axis of said speaker being directed towardsaid horn portion, one side portion of said casing having an opening ofsubstantial area located above said speaker through which access to saidspeaker may be had, and a removable member secured to said casing toform a protective cover for said opening.

6. A housing for a sound reproducer comprising a body portion and a hornportion, said housing being formed of non-ferrous metal wherebycorrosion of the parts is prevented when the reproducer is used inexposed locations.

EDWIN JAY QUINBY.

GEORGE P. HOPKINS.

